Search results for " polyammonium"

showing 3 items of 3 documents

Speciation of chitosan with low and high molecular weight carboxylates in aqueous solution

2009

Quantitative data on the speciation of chitosan (310 kDa) with low and high molecular weight carboxylates in aqueous solution are reported. The following carboxylic ligands were considered: monocarboxylate (butyrate); dicarboxylates (malonate, succinate, azelate); tricarboxylate (1,2,3-propa- netricarboxylate); tetracarboxylate (1,2,3,4-butanetetracarboxylate); polyacrylates (2.0 and 20 kDa); polymethacrylate (5.4 kDa). The investigation was performed by potentiometry at t 1/4 25 C, at low ionic strength (without addition of supporting electrolyte) and at I 1/4 0:15 mol L 1 (NaCl). For all the systems the formation of (chitosan)LHi species was found (L 1/4 carboxylic ligand; i 1/4 1 to 4 de…

Chemical Health and SafetyAqueous solutionpolyammonium-polycarboxylate interactionsSupporting electrolyteLigandHealth Toxicology and MutagenesisInorganic chemistrychitosan; polyammonium-polycarboxylate interactions; Chemical speciation; sequestration; effect of ionic strength on sequestrationsequestrationToxicologyTricarboxylateMedicinal chemistrychitosan polyammonium polycarboxylate speciation sequestration ionic strenght.Chitosanchemistry.chemical_compoundMalonatechemistryIonic strengthChemical speciationSettore CHIM/01 - Chimica Analiticaeffect of ionic strength on sequestrationCarboxylatechitosanChemical Speciation & Bioavailability
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Binding of fluoride and carbonate by open chain polyammonium cations

2004

The formation of open chain polyammonium cation-fluoride and -carbonate complexes was studied by potentiometric and calorimetric techniques at t=25 degrees C. Several species of H(i)AL (A=amine; L=F(-), CO(3)(2-)) are formed in both systems with a mean stability log K=1.0zeta (zeta=|z(anion)xz(cation)|) and log K=2.0zeta for fluoride and carbonate, respectively. The comparison with analogous systems (chloride and acetate for fluoride and hydrogenphosphate, sulfate and malonate for carbonate) showed that fluoride and carbonate form the most stable species with open chain polyammonium cations, among low molecular weight anions. The N-alkyl substitution does not play negligible role in the sta…

Open chain polyammonium cationCarbonatePotentiometric titrationInorganic chemistryComplex formationCalorimetryThermodynamic parametersMedicinal chemistryChlorideAnalytical Chemistrychemistry.chemical_compoundMalonatechemistryPotentiometrymedicineCarbonateSettore CHIM/01 - Chimica AnaliticaAmmoniumAmine gas treatingSulfateFluorideFluorideAnion coordination chemistrymedicine.drugTalanta
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Speciation of chitosan-phosphate and chitosan-nucleotide systems in an NaCl aqueous solution

2010

AbstractThe speciation of chitosan (310 kDa) with organic (adenosine 5’-monophosphate, AMP, and adenosine 5’-triphosphate, ATP), and inorganic phosphorus containing ligands (phosphate and pyrophosphate) was investigated in NaCl aqueous solutions at I = 0.1mol L−1 and T = 25°C. For all the systems, the investigated results obtained gave evidence for the formation of (chitosan)LHi complex species (L = nucleotides, phosphate and pyrophosphate; i = 1 to 4, but for AMP, i = 1 to 3). The stability data of complex species were used to calculate the sequestering ability of chitosan towards phosphorus compounds considered here, expressed as pL50 i.e., – log(total chitosan concentration) necessary to…

chemistry.chemical_classificationChemical Health and SafetyAqueous solutionChemistryLigandHealth Toxicology and MutagenesisPhosphorusInorganic chemistrychemistry.chemical_elementToxicologyPhosphatePyrophosphateAdenosineChitosanchemistry.chemical_compoundchitosan nucleotides phosphorus containing ligands chemical speciation polyammonium-phosphate interaction polyammonium-nucleotide interactionmedicineNucleotideSettore CHIM/01 - Chimica Analiticamedicine.drug
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